23 December, 2022

Spatio-temporal differences in pollinator species richness, abundance and conservation status in a Mediterranean island

 By Serra et al.

A syrphid fly visting flowers

Understanding the diversity patterns of pollinators and their interactions with plants is crucial to design effective conservation plans. The Mediterranean basin is a hotspot of pollinator diversity. Nevertheless, we need to know how distributed it is in the region and its conservation status. We aim to answer these questions in this region: Which are the most prevalent pollinator functional groups and how diverse are they? Which are the most specialised and generalised species? To what extent are they threatened?

In this study, we analysed and compar
ed data gathered over two years from three main habitats on the island of Mallorca: rocky coastal, coastal dune and mountainous. We had two more years of data from the coastal dune system to examine the effect of a perturbation in the area. We described the pollinator community composition, species richness and diversity for the three habitats. The differences we detected likely respond to differences in floral resource availability, pollinator mobility skills, and thermal constraints. The degree of specialisation of a given pollinator species, regardless of the functional group to which it belongs, was context-dependent. Some native and endemic species are threatened; thus, conservation strategies should be planned for them and further studied, especially their role in the community. We highlight that most pollinator species do not have an IUCN conservation status; for some groups, such as coleopterans, dipterans, hoverflies and wasps, almost no species is catalogued.

Read the scientific publication in JPE here.

Pollen accumulation on hawkmoths varies substantially among moth-pollinated flowers

By Smith et al.

Manduca sexta visits Oenothera harringtonii
Examining the pollen carried by flower visitors such as bees or moths is an excellent way to forensically reconstruct their behavior, such as the types of flowers they were visiting. This reconstruction, however, requires some assumptions: for example, to reconstruct the relative frequency with which they visited different flowers, you must assume that pollen from different flowers is picked up at similar rates. We tested this assumption for a number of flowers that are visited by hawkmoths, and found that despite similar natural pollinators the plants differed substantially in the amount of pollen they placed on the moths. Our findings suggest that comparisons within plant species (e.g., the amount of primrose pollen on two different pollinators) are likely sound, but that comparisons across plant species (e.g., the amount of primrose vs rock trumpet pollen on a single pollinator individual) should be cautious.  

Read the scientific publication in JPE here.